Transcriptional activation of alpha 1(III) procollagen gene in Tsk2/+ dermal fibroblasts

Transient transfection experiments into Tsk2/+ and normal dermal fibroblasts were performed using four successively shorter Col3a1 promoter deletion constructs: #103, #110, #114, and #120 fused to the chloramphenicol-acetyl-transferase (CAT) reporter gene. The transcriptional activity in Tsk2/+ and normal dermal fibroblasts driven by the three longer constructs was equal. With the shortest construct, #120 (-96 to +16bp) the transcriptional activity in Tsk2/+ fibroblasts was 25 times higher than in normal fibroblasts. Electrophoretic mobility shift assays with a labeled #120 probe revealed that increased DNA-protein binding occurred with nuclear extracts prepared from Tsk2/+ fibroblasts and that this binding was displaced by consensus Sp1 and NF-1 oligonucleotide sequences. These data indicate that sequences from -96 to +16bp of the Col3a1 promoter play an important role in the upregulated expression of this gene in Tsk2/+ fibroblasts and that the promoter contains sequences which bind the trans-acting nuclear factors, Sp1(like) and NF-1(like).